Charging pads are used to wirelessly transfer power from a transmitter of the charging pad to a receiver of a receiving device, such as a mobile phone or tablet computer. To transfer power from a charging pad to the receiving device, the receiving device may be placed on the charging pad by a user. Typically, an area of the charging pad is designated for placement of the receiving device. If the user does not correctly place the receiving device on the charging pad (e.g., does not align the receiving device with the designated area), power may be transferred at low efficiency or not at all. To account for misplacement (e.g., misalignment) of the receiving device on the charging pad, the charging pad may be designed to have a charging area, such as an active area defined by an electromagnetic field produced by the transmitter, that is larger than an area of the receiver. To generate a larger charging area for improved tolerance for misplacement, charging pads typically have one or three coils. As the number of inductive coils increases, so does a cost of producing each charging pad.
A charging pad may be configured to transfer power to different receiving device models of different receiving device types. As a variety of receiving device models and receiving device types increases, the charging area of the charging pad typically increases. Increasing the charging area requires additional components and complexity for the transmitter, which translates into increased costs for producing the charging pad.